Yeah
very nice fans. I have one of the 24V models - got it for £5 ($7.50) inc two plastic guards.

At full voltage it blows a gale, pointed it at a 80 mm fan and it spun the blades, this from about 8 inches. Noisy at full power, you definitely want to throttle these things back.

The 24V is really quiet at 7V, and reasonable at 12V, above that the whooshing air starts to get noisy